1. Field of the Invention
The present technology relates to the field of antimicrobial protection, particularly antimicrobial activity in close proximity to environments that need to be protected from or cleansed of microbial or chemical material that might be of concern. These include closed and open environments, and environments adjacent patients or users. The present technology also describes systems for delivery of the antimicrobial activity. The present technology relates to the field of antimicrobial protection, particularly antimicrobial activity in close proximity to hard surfaces, enclosed environments, rooms, and the bodies of patients. In particular, the field relates to the use of antimicrobial, antiodor and chemical modification agents that are active in the presence of water and/or lower molecular weight alcohols (e.g., C1-C6 alcohols).
2. Background of the Art
Historically, soils contaminated by solvents, oils, waste spillage and similar organic materials through leakage from storage or piping, accidental spills or inadequate disposal have been managed in several ways. Representative of the approaches which have been taken are: (1) excavation and reburial in an approved landfill; (2) soil flushing using recovery and recharge wells; and (3) in-situ biological treatment using supplemental nutrients and possibly supplemental bacteria. Other forms of localized antimicrobial activity use heat, disinfectants, aerosols and the like, but have limited applications, and highly diverse systems are created for different environments to be treated.
These land treatment methods particularly have not been entirely satisfactory for a host of technical, legal and cost reasons. Excavation and reburial of even moderate size tracts of contaminated soil is enormously costly. Moreover, even properly designed and operated state-of-the-art landfills have been found to leak. Soil flushing has serious technical limitations in that very large volumes of water must be flushed through the soil to sufficiently lower contaminant concentrations. In-situ biological treatment also possesses drawbacks, among them its unsuitability in areas with low groundwater and its high cost and the need to introduce new bacteria into an ecological region.
An alternative method of treatment for soils containing easily volatilized contaminants was attempted by the U.S. Environmental Protection Agency (“EPA”) in 1984. The contaminated soil, containing 1,1,1 trichloroethane, trichloroethene, toluene, ethyl benzene and ortho-, meta-, and para-xylene in concentrations from 10,000 to 110,000 ppb., was fed through an asphalt drying unit, also known in the industry as an aggregate dryer or rotary kiln. The drying unit included a liquid propane burner at one end which supplied combustion gases at 375° F. to the interior of the dryer. From exposure to the 375° F. gas, the contaminants were vaporized and the combined mixture of gases passed through a cyclone and bag house for removing particulate emissions, and then discharged directly to the atmosphere. The treated soil was discharged from the dryer, collected and then returned to the site.
Although the foregoing method was reported to be effective in reducing the concentrations of some contaminants by at least 99%, serious drawbacks were evident. Volatile organic compounds (“VOC's”) removed from the soil being treated were discharged to the atmosphere, thus decontaminating one medium, the soil, at the expense of polluting another medium, the air. In order to dilute the concentration of emitted VOC's in the ambient air, and because of local air discharge requirements, the dryer could only be operated at a feed rate of 10-15 tons of soil per hour, rather than the design rate of 100 tons/hour. Localities with more stringent air quality regulations would necessitate an even lower feed rate. Furthermore, the dryer could only be operated in dry weather conditions to prevent the emitted VOC's from being scrubbed from the atmosphere by rainfall, and thus returned to the soil.
For a proper site remediation project, both contaminated soil and contaminated groundwater must be cleaned. The contamination becomes very serious if the groundwater is a drinking water source. About 70 percent of potable water in the U.S.A. is supplied by groundwater. Site contamination, which is a national major concern, is about 71 percent caused by industrial accidents (chemical spills, tank leaks, etc.), 16 percent caused by railroad or truck's chemical accidents, and 13 percent caused by leachates from lagoons or dumpsites.
The primary reason for cleaning soil is public health protection. The primary reasons for treating groundwater are: potable use (39 percent), clean-up of aquifer to prevent spread of contamination (48 percent), and industrial and commercial use (13 percent). In any case, the potentially hazardous VOCs must be removed. Timely clean-up of aquifer to prevent spread of contamination is extremely important because the damage can be beyond repair if the spread of contamination is too wide.
The present technologies for ground and groundwater treatment include: air stripping tower without air emission control, non-regenerative gas phase granular activated carbon, chemical oxidation, non-regenerative liquid phase granular activated carbon, active charcoal fiber, biological processes, ion exchange, ultrafiltration, H2O2 treatment, reverse osmosis (RO), ozonation, lime softening, ultraviolet (UV), chemical coagulation, sedimentation, filtration and halogenation (e.g., chlorination, bromination and iodization). Air stripping tower without air emission control is the most common process for VOCs removal, but is not acceptable in many states. Liquid-phase granular activated carbon (GAC) contactor is technically feasible for water purification, but may be economically unfeasible when it is used alone. Chemical oxidation alone or UV alone is not cost-effective for VOCs reduction. Certain chemicals may even give undesirable residuals. Ultrafiltration and RO are excellent post-treatment process, requiring adequate pretreatment for cost reduction. Biological process is very efficient for removal of organic contaminants, but causes air pollution and requires thorough disinfection.
While conventional ozonation, UV, RO and chlorination are all effective disinfection processes, they all require separate reactors.
The story is quite different for soil treatment are quite limited and more narrowly focused because of the complexities in working with masses and volumes of solids. The present technologies for soil cleaning include: surfactant washing, neutralization, solidification, incineration, chemical oxidation, bio-oxidation, lime treatment, venting, and the like.
U.S. Pat. No. 7,033,509 (Klein) discloses an iodine fluid purification process using a source of fluid and means for delivery of iodine to the source of fluid for use in the purification process. The process provides a means for recovery of the iodine and/or iodine and/or other iodine species derived from the iodine, from the fluid.
U.S. Pat. No. 5,176,836 discloses a water purification process or method by introduction of molecular iodine into the water supply to impart a desired iodine residual wherein the water is passed through an iodinated anion exchange bed wherein the concentration of I2 in the flowing water gradually decreases and the ion bed is recharged by treatment with an aqueous iodine solution produced by flowing water through a bed of iodine crystals having connections in parallel with the ion exchange bed and activated periodically e.g., by a timer, by measured flow of water or by residual level to recharge the bed. That system provides for long term microbiological control in water suitable for potable activities.
The majority of patents relates to the direct or indirect treatment of water to remove microbes. Such disclosures are shown in U.S. Pat. No. 6,863,905; the use of free elemental iodine to kill or inactivate a large range of microbes (bacteria, virus and other pathogens) particularly in protein-containing solutions such as human blood, human plasma or fractions thereof is described in U.S. Pat. Nos. 5,019,495; 5,128,149; 5,128,150; 5,186,945; 5,360,605; 5,370,869; 5,589,072; and 5,609,864; pentavalent iodine-impregnated resins U.S. Pat. No. 5,635,063; provision of potable water U.S. Pat. Nos. 6,139,731 and 6,071,415; 5,324,438 describes a process for oxidizing a compound comprises contacting the compound with iodide ions and irradiating the iodide ions with UV light of a wavelength sufficient to generate iodine atoms. The compound is then oxidized with the resulting iodine atoms. The iodine atoms are reduced to iodide ions as a result of the oxidation of the compound.
Pesticides can influence soil microbial activity, at times paradoxically. Application of paraquat led to buildup of fungi and bacteria, but reductions in CO2 production, cellulose degradation, and nitrogenase activity. Sometimes selective destruction of predators and the resultant buildup of their microbial prey can occur. For example, glyphosate or diquat+paraquat application led to the buildup of Gaeumannomyces graminis var. tritici, the causal agent of take-all disease of wheat. Inoculation with untreated soil led to suppression of the pathogen in the treated soil, suggesting the possible role of microbial antagonists.
Nitrification and symbiotic nitrogen fixation are especially sensitive to disruption by pesticides, probably in part due to the small numbers of species involved in these processes.
There are many instances where aqueous materials are retained in contact with animal bodies and in which there is potential for unwanted and even dangerous and significant microbial growth or microbial introduction into the animal body. For example, in the application of materials wound dressing, menstrual products, patches, diapers, pads and the like, moisture from the animal body or ambient conditions or the materials themselves can introduce microbes to the environment and those microbes can proliferate in the vicinity of the materials when moisture is present. The uncontrolled growth of random microbes is seldom beneficial and has been the subject of significant efforts at control.
U.S. Pat. Nos. 6,328,929 and 6,146,725 (Code) describe reagent and delivery compositions for formation of iodine gas or iodine in water.
Many applications exist where it is still necessary or at the very least an advantage for improves systems and agents to be present which demonstrate anti-bacterial, anti-mycotic activity or both, resulting in the control of bacterial and/or fungal growth. For example, an apparatus or article as a whole or in part may have the property of suppressing bacterial and fungal growth. Control of bacterial and/or fungal growth may be through the prevention or inhibition of the growth of such microbes.